NSF Digital Government surveillance geoinformatics project, federal agency partnership and national applications for digital governance.

Geoinformatic hotspot surveillance system

Geographic and Network Surveillance for Arbitrarily Shaped Hotspots Center for Statistical Ecology and Environmental Statistics G.P. Patil, R. Acharya, W.L. Myers, P. Patankar, Y. Cai, and S.L. Rathbun The Penn State University, University Park, PA 16802 R. Modarres George Washington University, Washington, D.C. Overview Geospatial Surveillance Upper Level Set Scan Statistic System Spatial-Temporal Surveillance Typology of Space-Time Hotspots Hotspot Prioritization Ranking Without Having to Integrate Multiple Indicators Surveillance Geoinformatics for Hotspot Detection, Prioritization, Early Warning and Sustainable Management Upper Level Set Scan System Definition: A hotspot is that portion of the study region with an elevated risk of an adverse outcome Example: West Nile Virus First isolated in 1937, this mosquito born disease, indigenous to north Africa, the Middle East and west Asia was first introduced into the United States in 1999. Example: Lyme Disease Infections from the bacterium Borelia burgdorfei vectored by ticks from the genus Ixodes. Example: Human-environment indicator values for 16 European countries. Changing Connectivity of ULS as Level Drops g Comparison of ULS Scan with Cylindrical Scan ULS Scan Disease Count Quintiles Population Quintiles Year Disease Rates Cylindrical Scan Features of ULS Scan Statistic: Identifies arbitrarily shaped hotspots Applicable to data on a network Confidence sets and hotspot ratings Computationally efficient Generalizes to space-time scan 1997 1998 Haase Diagram Poset Prioritization System Objective: Prioritize or rank hotspots based on multiple indicator and stakeholder criteria without having to integrate indicators into an index, using Haase diagrams and partially ordered sets. Example: Prioritization of disease clusters with Multiple Indicators Disease Rate Quintiles Likelihood Quintiles 1999 2000 There are a total of 3,764,448 admissible linear extensions. The cumulative rank function for Sweden exceeds that of all remaining countries. The crf’s of all countries dominate that of Ireland. The remaining countries cannot be uniquely ordered based on their crf’s. Belgium, Netherlands and United Kingdom have identical crf’s. Comparison of ULS Scan with Circular Scan 2001 ULS Scan Circular Scan Admissible linear extensions are comprised of rankings compatible with the rankings of all indicators. Treating each linear extension as a voter, the cumulative rank function is obtained from the frequencies at which each object receives each rank. 2002 2003 The crf’s also form a partially ordered set. There are only 182 admissible linear extensions for this poset, yielding the cumulative rank function: Federal Agency Partnerships CDC DOD EPA NASA NIH NOAA USFS USGS Confidence set for ULS Hotspot Hotspot Membership Rating National Applications and Case Studies Biosurveillance Carbon Management Costal Management Community Infrastructure Crop Surveillance Disaster Management Disease Surveillance Ecosystem Health Environmental Justice Sensor Networks Robotic Networks Environmental Management Environmental Policy Homeland Security Invasive Species Poverty Policy Public Health Public Health and Environment Syndromic Surveillance Social Networks Stream Networks One more iteration yields the rankings in the data table.

Demonstration Example Data Population Cases Disease Rate Likelihood

Demonstration Example Upper Level Set Tree: Cells 12 9 2 1 3 4 5 6 7 8 13 14 15 16 17 18 19 11 10

Demonstration Example Upper Level Set Tree: Zones 12 9 2 1 3 4 5 6 7 8 13 14 15 16 17 18 19 11 10 [3] [3,18] [3,18,0] [8] [3,18,0,4] [17] [8,7] [14] [3,18,0,4;8,7;19] [17,16] [17,16;14;15] [3,18,0,4,8,7,19,5;17,16,14,15;11]

ULS Scan ULS Scan Disease Rate Hotspots using ULS 133.78 120.90 0.19 31.55 31.22 19.33 Disease Rate Hotspots using ULS ULS Scan Hotspot 1 Hotspot 2 (red) (orange) Log Likelihood 133.78 120.90 p-value 0.19 0.395 Relative Risk 2.05 2.37

Confidence Set for ULS Hotspot Hotspot membership rating

ULS Scan (With modified rates) 216.82 3.09 1.58 0.12 Disease Rate Hotspots using ULS ULS Scan Hotspot 1 (red) Log Likelihood 216.82 p-value 0.03 Relative Risk 15.46

Confidence Set for ULS Hotspot Hotspot membership rating